1. Filed of the Invention
The present invention relates to a composite high frequency component and a mobile communication device including the same, and more particularly to a composite high frequency component which can be used in plural different mobile communication systems and a mobile communication device including the same.
2. Description of the Related Art
At present, in Europe, as a mobile communication device, a dual band portable telephone has been proposed which can be operated in plural frequency bands, for example, DCS (Digital Cellular System) employing the 1.8 GHz band, and GSM (Global System for Mobile Communications) operative in the 900 MHZ band.
FIG. 14 is a block diagram showing a part of the configuration of a dual band portable telephone as a conventional mobile communication device, illustrating an example of the combination of DCS in the 1.8 GHz band and GSM in the 900 MHZ band. The dual band portable telephone is equipped with an antenna 1, a diplexer 2, and two signal paths, namely, the DCS system 3 and the GSM system 4.
The diplexer 2, for transmission, performs the function of coupling transmitting signals from the DCS system 3 or GSM system 4, and for reception, does that of distributing received signals to the DCS system 3 or GSM system 4. The DCS system 3 is composed of a high frequency switch 3a for separating its transmission section Txd and its reception section Rxd, and a notch filter 3b for attenuating second and third harmonics of DCS. The GSM system 4 is composed of a high frequency switch 4a for separating its transmission section Txg and its reception section Rxg, and a notch filter 4b for attenuating third harmonics of GSM.
The high frequency switches 3a and 4a are separately provided with controlling power supplies Vc 61 and Vc 62 for on-off controlling the switches, respectively.
Hereinafter, the operation of the dual band portable telephone will be described in reference to the case that the DCS system 3 is used as an example. For transmission, with the high frequency switch 3a, the transmission section Txd is turned on, and a transmitting signal from the transmission section Txd is fed to the notch filter 3b. The transmitting signal, passed through the notch filter 3b is wave-combined in the diplexer 2, and sent through the antenna 1. On the other hand, for reception, a receiving signal, received through the antenna 1, is wave-separated in the diplexer 2. The receiving signal form the antenna 1 is fed to the notch filter 3b. With the high frequency switch 3a, the reception section Rxd is turned on, so that the receiving signal is fed through the notch filter 3b to the reception section Rxd. In the case that the GSM system 4 is used, the transmission and reception are carried out by similar operation.
Further, in Europe, as a mobile communication device, a triple band portable telephone has also been proposed which can be operated in plural frequency bands, for example, by DCS (Digital Cellular System) and PCS (Personal Communication Services) which can be operated in the 1.8 GHz band, and GSM (Global System for Mobile Communications) operative in the 900 MHZ band.
FIG. 15 is a block diagram showing the front end portion of a conventional triple band portable telephone as an example. In this case, as the first and second communication systems operative at adjacent frequencies, DCS and PCS using the 1.8 GHz band, and also, as the third communication system applicable at a different frequency from the first and second communication systems, GSM operative in the 900 MHZ band are employed, respectively.
The front end portion of the triple band portable telephone is provided with an antenna 1a, a diplexer 2a, first through third high frequency switches 3a through 5a, and first and second filters 6a and 7a. The diplexer 2a has the function of coupling transmitting signals by DCS, PCS, or GSM in the case of transmitting, and distributing receiving signals to DCS, PCS, or GSM in the case of receiving. The first high frequency switch 3a switches the transmission section side of DCS and PCS to the reception section side of DCS and PCS and vice versa. The second high frequency switch 4a has the function of switching the reception section Rxd side of DCS to the reception section Rxp side of PCS and vice versa. The third high frequency switch 5a has the function of switching the transmission section Txg side of GSM to the reception section Rxg side thereof and vice versa. The first filter 6a has the function of passing transmittingxe2x80x94receiving signals by DCS and PCS and attenuating second and third harmonics, and the second filter 7a has the function of passing transmittingxe2x80x94receiving signals by GSM and attenuating the third harmonics.
Hereinafter, the operation of the triple band portable telephone, that is, first, the case of DCS will be described. In the case of transmission, with the first high frequency switch 3a, the transmission section Txdp common to that of PCS is turned on so that a transmitting signal from the transmission section Txdp is fed to the first filter 6a. The transmitting signal passed through the first fitter 6a is wave-associated in the diplexer 2a and sent through the antenna 1a. In the case of receiving, a receiving signal received through the antenna 1a is wave-separated in the diplexer 2a. The receiving signal from the antenna 1a is fed to the first filter 6a which is on the DCS and PCS side. With the first high frequency switch 3a, the reception section side is turned on so that the receiving signal passed through the first filter 8a is fed to the second high frequency switch 4a. With the second high frequency switch 4a, the reception section Rxd of DCS is turned on, so that the receiving signal passed through the second high frequency switch 4a is fed to the reception section Rxd of DCS. In the case of PCS used, the transmission and reception is performed by similar operation.
Thereafter, the case of GSM will be described. In the case of transmission, with the third high frequency switch 5a, the transmission section Txg is turned on so that a transmitting signal from the transmission section Txg is fed to the second filter 7a. The transmitting signal passed through the second filter 7a is wave-associated in the diplexer 2a and sent through the antenna 1a. In the case of receiving, a receiving signal received through the antenna 1a is wave-separated in the diplexer 2a. The receiving signal from the antenna 1a is fed to the second filter 7a which is on the GSM side. With the third high frequency switch 5a, the reception section Rxg is turned on, so that the receiving signal passed through the second filter 7a is fed to the reception section Rxg.
However, in the above-described dual band portable telephone which is one of conventional mobile communication devices, the antenna, the diplexer, and the high frequency switches and filters constituting the DCS system and the GSM system are discrete, and are mounted one by one on a circuit board. Accordingly, it is necessary to provide a matching circuit between the diplexer and the high frequency switches in order to assure the matching, the attenuation, or the isolation characteristics. For this reason, the number of the components is increased, causing the increase of the mounting area. As a result, it is necessary to employ a large circuit board. This causes the trouble that the dual band portable telephone (mobile communication device) is increased in size.
Further, in the above-described dual band portable telephone which is one of conventional mobile communication devices, the DCS system and the GSM-system are on-off controlled by means of the two separate controlling power supplies only, connected separately to the transmission sides of the high frequency switches. Thus, during the transmission, the high frequency switches of the DCS system and the GSM system are differently operated, which causes the distortion problem with respect to the off-side high frequency switch. Furthermore, it is troublesome that the control of the high frequency switches for the transmission becomes complicate.
Further, in the above-described triple band portable telephone which is one of conventional mobile communication devices, the antenna, the diplexer, and also, the high frequency switches and the filters constituting the DCS system and GSM system are discrete, and mounted on one circuit board. Therefore in order to assure the matching, the attenuation, and the isolation characteristics of the respective elements, it is necessary to provide a matching circuit between the diplexer and the high frequency switches. Accordingly, the number of the elements is risen, bringing the increase of the mounting area, and thereby, the large circuit board is needed. Thus, there is the problem that the size of the triple band portable telephone (mobile communication device) is large in size.
To overcome the above described problems, preferred embodiments of the present invention provide a composite high frequency component for which a matching circuit is unnecessary and of which the circuit can be miniaturized, and of which the distortion at transmission is inhibited, and the control of the transmission can be simplified, and a mobile communication device including the same.
One preferred embodiment of the present invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; said diplexer, said high frequency switch, and said filters being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.
According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers. Thus, the matching and adjustment between the diplexer and the high frequency switches can be easily performed. It is unnecessary to provide a matching circuit for matching and adjusting the diplexer and the high frequency switches, and moreover, the high frequency switches and the filters.
Accordingly, the number of the elements can be reduced, and thereby, the circuit board for forming the microwave circuit having the plural signal paths can be miniaturized.
In the above described composite high frequency component, the plural filters may be connected to the transmission section sides which are in the latter stage with respect to the high frequency switches.
According to the above described composite high frequency component, the filters are connected to the transmission section sides which are in the latter stage with respect to the high frequency switches, respectively. Thus, the distortion of the transmitting signal, caused by the high power amplifiers arranged in the transmission sections, can be attenuated. Thus, the insertion loss in the reception sections can be improved.
In the above described composite high frequency component, each of the plural filters may be a notch filter.
By using a notch filter, only the band area around the second and third harmonics can be attenuated to thereby the deleterious effect thereof on a band-area around the fundamental wave is reduced. Therefore, an insertion loss around the band-area including the fundamental wave is reduced more compared with a low-pass filter and a band-pass filter which attenuates whole of the high harmonics. Accordingly, the loss of the composite high frequency component is improved.
In the above described composite high frequency component, the diplexer may be composed of a first inductance element and a first capacitance element, each of the plural high frequency switches may be composed of a switching element, a second inductance element, and a second capacitance element, and each of the plural filters may be composed of a third inductance element and a third capacitance element, and the switching elements, the first through third inductance elements, and the first through third capacitance elements may be contained in or mounted onto the ceramic multi-layer substrate and connected by means of a connecting means formed inside the ceramic multi-layer substrate.
According to the above described composite high frequency component, the diplexer comprises the first inductance elements and t he first capacitance elements, each of the high frequency switches does the switching elements, the second inductance elements, and the second capacitance elements, each of the filters does the third inductance element and the third capacitance elements, and moreover, they are contained in or mounted onto the ceramic multi-layer substrate and connected by means of a connecting means formed inside the ceramic multi-layer substrate. Thus, the composite high frequency component can be formed on one ceramic multi-layer substrate, and its miniaturization can be realized. In addition, the loss, caused by the wiring between the elements, can be improved. As a result, the overall loss of the composite high frequency component can be improved.
Further, the strip line electrodes to function as the inductors are contained in or mounted onto the ceramic multi-layer substrate. With the wavelength shortening effect, the lengths of the strip line electrodes to function as the respective inductance elements can be reduced. Therefore, the insertion loss caused by these strip-line electrodes can be enhanced. The miniaturization of the composite high frequency component and the reduction of the loss can be realized. As a result, the miniaturization and the high qualities of the mobile communication device including the composite high frequency component can be also attained.
In the above described composite high frequency component, the second inductance elements constituting the plural high frequency y switches may contain parallel trap coils and choke coils, and said parallel trap coils and said choke coils may be formed of chip coils.
According to the above described composite high frequency component, of the second inductance elements as the constituents of the plural high frequency switches, the choke coils and the parallel trap coils are chip coils. Therefore, the high frequency switches can be designed so as to have a low loss, and the band can be widened.
Another preferred embodiment of the present invention provides a mobile communication device including any one of the above described composite high frequency component.
The above described mobile communication device employs the composite high frequency component which is small in size and has a low loss. Therefore, the miniaturization and the high qualities of the mobile communication device including the high frequency switch can be attained.
Yet another preferred embodiment of the present invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; each of said plural high frequency switches including a first switching element connected to the transmission section side and a second switching element connected to the reception section side; and said plural high frequency switches being on-off controllable with a first common controlling power supply connected to the plural high frequency switches on the transmission section sides thereof.
According to the above described composite high frequency component, the plural high frequency switches are on-off controlled by means of the first common controlling power supply connected to the transmission section sides. Therefore, for transmission, the plural high frequency switches can be turned on at the same time, so that the higher harmonic distortion caused by the high frequency switches can be reduced, and the characteristics of the composite high frequency component can be enhanced.
Further, the control of the high frequency switches can be simplified. Thus, the transmission and reception by the mobile communication device including the composite high frequency component can be simply controlled.
Moreover, as the first controlling power supply, only one power supply is used. Thus, the wiring and arrangement on a substrate for mounting the composite high frequency component such as printed board can be simplified. Thus, the miniaturization of the mounting board can be realized. In addition, the mobile communication device including the composite high frequency component can be reduced in size.
Yet another preferred embodiment of the present invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; each of said plural high frequency switches including a first switching element connected to the transmission section side and a second switching element connected to the reception section side; said plural high frequency switches being on-off controllable with a first common controlling power supply connected to the plural high frequency switches on the transmission section sides thereof and a second common controlling power supply connected to the high frequency switches on the reception sides thereof.
According to the above described composite high frequency component, the plural high frequency switches are on-off controlled by means of the first common controlling power supply connected to the transmission section side and the second common controlling power supply connected to the reception section sides. Thus, for transmission, all the first and second diodes of the plural high frequency switches can be securely turned on, and the high frequency switches of the DCS and GSM systems can be securely turned on at the same time. Accordingly, the higher harmonic distortion during the transmission caused by the high frequency switches can be further reduced, and the characteristics of the composite high frequency component can be further enhanced.
As the first and second controlling power supplies, only one power supply is used, respectively. Thus, the wiring and arrangement on the substrate for mounting the composite high frequency component such as the printed board can be simplified, and the miniaturization of the substrate for mounting is realized. In addition, the mobile communication device including the composite high frequency component can be reduced in size.
In the above described composite high frequency component, the plural filters may be arranged between the plural high frequency switches and the transmission section sides, respectively.
According to the above described high frequency component, the filters each are arranged between the high frequency switches and the transmission section sides. Thus, the distortion of the transmitting signal, caused by the high power amplifiers arranged on the transmission section sides, can be decreased. Accordingly, the insertion loss on the reception sides can be improved.
In the above described composite high frequency component, the diplexer, the plural high frequency switches, and the filters may be integrated into a ceramic multi-layer substrate composed of plural ceramic sheet layers laminated together.
According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of the plural ceramic sheet layers. Thus, the matching and adjustment between the diplexer and the high frequency switches can be easily performed. Accordingly, it is unnecessary to provide a matching circuit between the high frequency switches and the filters.
Accordingly, the number of the elements can be reduced, which enables the miniaturization of the circuit substrate on which the microwave circuit including plural signal paths is formed.
In the above described composite high frequency component, the diplexer may be composed of first inductance elements and first capacitance elements, each of the plural high frequency switches may be composed of the first switching element and the second switching element, second inductance elements, and second capacitance elements, and each of the plural filters may be composed of a third inductance element and third capacitance elements, and the first switching elements and the second switching elements, the first through third inductance elements, and the first through third capacitance elements may be contained in or mounted onto the ceramic multi-layer substrate and connected by means of a connecting means formed inside the ceramic multi-layer substrate.
According to the above described composite high frequency component, the diplexer is constituted by the first inductance elements and the first capacitance elements, each high frequency switch by the switching elements, the second inductance elements, and the second capacitance elements, and each filter by the third inductance elements and the third capacitance elements. Further, these elements are contained in or mounted onto the ceramic multi-layer substrate, and connected by means of a connecting means formed inside the ceramic multi-layer substrate. Thus, the composite high frequency component can be formed on one ceramic multi-layer substrate and can be miniaturized. In addition, the loss due to the wiring between the elements can be reduced. As a result, the overall loss of the composite high frequency component can be improved.
With the wave-length shortening effect, the lengths of the strip line electrodes as the respective inductance elements can be reduced. Therefore, the insertion loss caused by these strip-line electrodes can be enhanced. As a result, the miniaturization of the composite high frequency component and the reduction of the loss can be realized.
In the above described composite high frequency component, the second inductance element constituting each of the plural high frequency switches may be formed of a choke coil, and the choke coil is integrated into the ceramic multi-layer substrate.
According to the above described composite high frequency component, the choke coils and the parallel trap coils of the second inductance elements which constitute the plural high frequency switches are chip coils. Thus, the high frequency switches can be designed so as to have a low loss, and moreover, its band can be widened.
Yet another preferred embodiment of the present invention provides a mobile communication device including any one of the above described composite high frequency component.
According to the above described mobile communication device, the composite high frequency component which is small in size and has a less higher harmonic distortion is employed. Therefore, the miniaturization and the high performance of the mobile communication device including the composite high frequency component can be realized.
Yet another preferred embodiment of the present invention provides a composite high frequency component provided with a front end portion so formed as to correspond to first and second communication systems operative at adjacent frequencies, and a third communication system operative at a frequency different from those of the first and second communication systems, comprising: a diplexer for coupling transmitting signals from said first through third communication systems in the case of transmission and for distributing receiving signals to said first through third communication systems in the case of reception; a first high frequency switch for separating the transmission section of said first and second communication systems and the reception section of the first and second communication systems from each other; a second high frequency switch for separating the reception section of the first communication system and the reception section of the second communication system from each other; a third high frequency switch for separating the transmission section of said third communication system and the reception section thereof from each other; a first filter for passing transmissionxe2x80x94reception signals of said first and second communication systems; and a second filter for passing transmissionxe2x80x94reception signals of said third communication systems; and the composite high frequency component being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.
According to the above described composite high frequency component, the diplexer, the first through third high frequency switches, and the first and second filters, which constitute the composite high frequency component, are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers, the matching, attenuation, or isolation characteristics can be assured. This makes it unnecessary to provide a matching circuit between the diplexer and the first and third high frequency switches.
Thus, the number of the elements can be reduced, which enables the miniaturization of the composite high frequency component which constitutes the front end portion corresponding to the first through third communication systems.
In the above described composite high frequency component, at least one of said first and second filters may be arranged in the post-stage with respect to the high frequency switch.
According to the above described composite high frequency component, the filters are arranged between the high frequency switches and the transmission sections. Thus, the distortion of a transmitting signal, caused by high power amplifiers formed in the transmission sections can be reduced. Accordingly, the insertion loss of the reception sections can be improved.
In the above described composite high frequency component, the diplexer may comprise a first inductance element and a first capacitance element, each of the first through third high frequency switches may comprise first and second switching elements, second inductance elements, and second capacitance elements, and each of the first and second filters may comprise a third inductance element and a third capacitance element; said first through third inductance elements, said first through third capacitance elements, and said first and second switching elements being contained in or mounted onto said ceramic multi-layer substrate and connected by a connecting means formed inside said ceramic multi-layer substrate.
According to the above described composite high frequency component, the diplexer comprises the first inductance elements and the first capacitance elements, the first through third high frequency switches do the first and second switching elements, the second inductance elements, and the second capacitance elements, respectively, the first and second filters do the third inductance elements and the third capacitance elements, respectively, and these elements are contained in or mounted onto the ceramic multi-layer substrate and connected by means of a connecting means formed inside the ceramic multi-layer substrate. Therefore, the composite high frequency component can be formed by use of one ceramic multi-layer substrate and further can be miniaturized. In addition, the loss caused by wirings between the elements can be improved. As a result, the overall loss of the composite high frequency component can be improved.
Further, with the wavelength shortening effects, the strip-line electrodes which function as the respective inductance elements can be shortened. Thus, the insertion losses due to these strip-line electrodes can be improved. As a result, the composite high frequency component can be miniaturized, and the reduction of the loss can be realized.
Yet another preferred embodiment of the present invention provides a mobile communication system including any one of the above described composite high frequency component.
The above described mobile communication device contains the composite high frequency component which is small in size and has a low loss. Accordingly, the mobile communication device having the composite high frequency component mounted thereto can be miniaturized and rendered high qualities.